There are known motorcycle trailers, but none with a hinged lift lid intermediate aerodynamic curvature of a front and a rear top of a box bed having correspondingly aerodynamic curvature of corners and with the lift lid having correspondingly aerodynamic curvature of lid sides in a manner taught by this invention. The hinged lift lid is hinged on a roadway side of the box bed for being lifted from an off-road side of the box bed.